1. Field of the Invention
The present invention generally relates to fiber optic connectors and, more particularly, is concerned with a wet-mateable connector for holding two optical fibers in optical alignment in high pressure undersea environments.
2. Description of the Prior Art
Fiberoptic (light wave) technology, a spin-off from the telecommunications industry, is being applied to terrestrial and undersea systems, both commercial and military. Undersea military surveillance systems depend increasingly on this technology for data communications. Inherent advantages of fiberoptics that make light-wave systems invaluable to the military are enhanced data security, immunity to electro-magnetic interference, low optical loss, high data speeds, low bit error rates, lightweight and radiation hardened.
However, the reliability of such systems rests largely on the design of the fiber optic connectors. The challenge in implementing undersea light-wave technology is to produce a low-cost, reliable, wet-mateable connector for undersea fiberoptics. Such a connector must join together two single-mode optical fibers, each with very small diameters, in a harsh seawater environment. A typical single-mode fiber has an optical core diameter of five to ten microns (one-tenth the diameter of a human hair). Mechanical misalignment of only one micron between the optical cores results in a twenty percent (approximately one decibel) loss in optical power.
Some of the performance objectives for a fiber optic wet-mateable connector are that the connector compensate automatically for undersea pressure, have a significant life span, align the optical cores with low loss, and be capable of undergoing several cycles of mating and demating at considerable depths using a robot or remote-controlled vehicle. For example, a connector imposing a loss of less than one-half decibel, having a life greater than two years and being capable of ten mate and demate cycles in sea water at water depths up to 20,000 feet using a remote controlled vehicle would satisfy the aforementioned performance objectives.
At the present time, it is believed that there are no undersea wet-mateable fiber optic connectors capable of meeting the above-mentioned performance objectives. Therefore, a need still exists for a connector design with the potential to reach these objectives if advanced undersea fiberoptic systems are to become a reality.